Twelve people died and 47 were injured in the Polish bus tragedy on the M3 motorway near Mezőkeresztes late last Sunday night. The bus, carrying pilgrims from Medjugorje in Bosnia and Herzegovina back to Poland, left the carriageway, plunged into a drainage ditch and overturned. Police preliminarily suspect the driver fell asleep at the wheel. A forensic vehicle expert has now outlined how long the driver may have been unconscious, how the crash unfolded and what might prevent similar tragedies in future.
Polish bus tragedy: how a few seconds proved fatal
Based on evidence at the scene, the driver appears to have lost alertness for only a matter of seconds. Sándor Boncsér, a court-certified automotive engineering expert, told Telex as little as two to four seconds of micro-sleep could have been enough to cause the catastrophe. At roughly 100km/h, the 24-tonne vehicle would have travelled more than 100 metres in four seconds with no one at the controls. If cruise control was engaged, the speed would barely have dropped before the driver regained consciousness.
Because motorways are cambered slightly to shed rainwater, the bus drifted gradually to the right after the driver nodded off. The Scania’s right-hand wheels left the tarmac, crossed the hard shoulder and mounted the embankment. On the steep slope, traction on the right-side wheels was lost, making it virtually impossible to steer the bus back onto the road.
The absence of a continuous crash barrier on this stretch meant there was nothing to arrest the vehicle’s departure from the carriageway. On the steep embankment the bus’s centre of gravity shifted laterally, causing it to roll over. The expert added that the roof structure may not have been designed to absorb the mass and kinetic energy involved, contributing to the severity of the crash.
Who stands the best chance of survival?
Seat-belt use significantly affects survival odds. On Tempo 100-rated coaches, motorway regulations require all passengers to wear seat belts, but with 50–60 travellers on board the driver cannot realistically check who has unbuckled during the journey. Reports that several passengers were thrown from the bus suggest many were not restrained.
How to prevent future tragedies
The most critical factor remains driver alertness. EU rules strictly govern driving and rest periods, although more flexible provisions for tourist-coach drivers have applied since 2024. Technology can also help: modern coaches may be fitted with systems that monitor fatigue, eye movement and steering patterns, alongside lane-departure warnings, active lane-keeping and emergency-brake assist.
Yet technology alone cannot eliminate risk. European Commission data suggest driver fatigue contributes to 15–20 per cent of road accidents. Hungary’s public road authority recorded 716 crashes between early 2020 and March 2026 in which the driver was confirmed to have fallen asleep.
If you missed our previous article concerning the tragedy: ‘People were shouting, trapped beneath the seats’ – exclusive interview, video and latest developments in Polish bus crash
What the driver now faces
The driver’s criminal liability has not yet been determined. Authorities must examine tachograph data, driving and rest periods, speed records and any possible mechanical faults. If convicted of causing a mass-casualty traffic accident resulting in death, he could face two to eight years’ imprisonment, plus fines and a multi-year driving ban. Sentencing will take into account his prior record and whether he breached traffic regulations.
The tragedy’s starkest lesson is that, with a vehicle weighing dozens of tonnes, even a few seconds’ loss of attention can prove fatal. By the time a driver realises the coach has left the road, its motion may already be irreversible.
‘It happened in seconds’: Another survivor reveals horror of deadly Polish bus crash on Hungary’s motorway
